What is Central Sleep Apnea?
Central sleep apnea is a sleep disorder in which you briefly stop breathing during sleep. The moments of apnea can occur repeatedly throughout the night. The interruption of your breathing happens may indicate a problem with your brain’s signaling. Your brain momentarily “forgets” to tell your muscles to breathe.
Central sleep apnea is not to be confused with obstructive sleep apnea. Obstructive sleep apnea is the interruption of breathing due to blocked airways. People who have central sleep apnea do not have blockages in their airways. The problem is in the connection between the brain and the muscles that let you breathe. Healthline.com
Central sleep apnea is much less common than obstructive sleep apnea. The American Sleep Apnea Association (ASAA) estimates that less than 20 percent of people with sleep apnea suffer from central sleep apnea. (ASAA)
What Causes Central Sleep Apnea?
Central sleep apnea occurs when your brain fails to transmit signals to your breathing muscles.
Central sleep apnea can be caused by a number of conditions that affect the ability of your brainstem — which links your brain to your spinal cord and controls many functions such as heart rate and breathing — to control your breathing. The cause varies with the type of central sleep apnea you have. Types include:
- Cheyne-Stokes breathing. This type of central sleep apnea is most commonly associated with congestive heart failure or stroke. This condition is characterized by a gradual increase and then decrease in breathing effort and airflow. During the weakest breathing effort, a total lack of airflow (central sleep apnea) can occur.
- Drug-induced apnea. Taking certain medications such as opioids — including morphine sulfate (Ms Contin, Avinza, others), oxycodone (Oxycodone HCL, Oxycontin, others) or codeine sulfate — may cause your breathing to become irregular, to increase and decrease in a regular pattern, or to temporarily stop completely.
- High-altitude periodic breathing. A Cheyne-Stokes breathing pattern may occur if you’re exposed to a very high altitude. The change in oxygen at this altitude is the reason for the alternating rapid breathing (hyperventilation) and under breathing.
- Complex sleep apnea. Some people with obstructive sleep apnea develop central sleep apnea while using continuous positive airway pressure (CPAP) for their sleep apnea treatment. This condition is known as complex sleep apnea because it’s a combination of obstructive and central sleep apneas.
- Medical condition-induced central sleep apnea. Several medical conditions may give rise to central sleep apnea of the non-Cheyne-Stokes variety.
- Idiopathic (primary) central sleep apnea. The cause of this uncommon type of central sleep apnea isn’t known. It results in repeated pauses in breathing effort and airflow. Mayo Clinic
Examples of related conditions include:
- heart attack
- congestive heart failure
- a weak breathing pattern called Cheyne-Stokes breathing
- encephalitis (an inflammation of the brain)
- arthritis in the cervical spine
- Parkinson’s disease (an age-related deterioration of certain nerve systems that affects movement, balance, and muscle control)
- surgery or radiation treatments in the spine
Central Sleep Apnea Symptoms
The primary observed symptom of central sleep apnea is short periods during sleep when breathing stops. Some people exhibit very shallow breathing instead of an actual stoppage of breathing. The lack of oxygen can cause you to wake up briefly and frequently throughout the night. You may wake up feeling short of breath. The apnea episodes can cause insomnia, too. Healthline.com
Common signs and symptoms of central sleep apnea include:
- Observed episodes of stopped breathing or abnormal breathing patterns during sleep
- Abrupt awakenings accompanied by shortness of breath
- Shortness of breath that’s relieved by sitting up
- Difficulty staying asleep (insomnia)
- Excessive daytime sleepiness (hypersomnia)
- Difficulty concentrating
- Mood changes
- Morning headaches
Although snoring indicates some degree of increased obstruction to airflow, snoring also may be heard in the presence of central sleep apnea. However, snoring may not be as prominent with central sleep apnea as it is with obstructive sleep apnea.
When to see a doctor
Consult a medical professional if you experience, or if your partner observes, any signs or symptoms of central sleep apnea, particularly the following:
- Shortness of breath that awakens you from sleep
- Intermittent pauses in your breathing during sleep
- Difficulty staying asleep
- Excessive daytime drowsiness, which may cause you to fall asleep while you’re working, watching television or even driving
Ask your doctor about any sleep problem that leaves you chronically fatigued, sleepy and irritable. Excessive daytime drowsiness (hypersomnia) may be due to other disorders, such as narcolepsy or obstructive sleep apnea. Mayo Clinic
Diagnosing Central Sleep Apnea
Your doctor will order a sleep study test called polysomnography to diagnose central sleep apnea. During polysomnography, your oxygen levels, brain activity, breathing pattern, heart rate, and lung function are monitored. You will be outfitted with a series of electrodes on your head and body to measure each function. The test is administered overnight as you sleep in a special sleep center.
Your doctor, a neurologist, and sometimes a cardiologist will view the results of your polysomnography. The results can help determine the underlying cause of your apnea.
A head or spinal magnetic resonance imaging (MRI) scan may also be used to diagnose central sleep apnea. MRI uses radio waves to generate images of your organs. The test may reveal structural abnormalities in your brainstem or spine that are causing central sleep apnea.
Treating Central Sleep Apnea
Management of underlying medical conditions is the first line of treatment for central sleep apnea. Congestive heart failure, Parkinson’s disease, and other heart or nervous system conditions can be controlled with medications. You may need to wean yourself off of opioid medications if these drugs are causing your breathing to stop during sleep. Your doctor may also prescribe medications such as acetazolamide to stimulate your breathing mechanism.
Oxygen supplementation and the regulation of air pressure during sleep are effective treatments for many people with central sleep apnea. These include:
- CPAP, or continuous positive air pressure, provides a steady source of pressure in your airways as you sleep. You wear a mask over your nose and mouth that delivers pressurized air throughout the night. CPAP is used to treat obstructive sleep apnea, but can also be beneficial for people with central sleep apnea.
- BPAP, or bi-level positive air pressure, adjusts the air pressure to a higher level when you inhale and a lower level when you exhale. BPAP is also delivered through a facemask.
- ASV, or adaptive servo-ventilation, monitors your breathing as you sleep. The computerized system “remembers” your breathing pattern. The pressurized system regulates the breathing pattern to prevent apnea episodes. Healthline.com
An online discussion of central sleep apnea prepared by experts at Minnesota’s Mayo Clinic breaks the disease down into five types:
- Primary CSA, which is the same as idiopathic CSA–the patient has no known related diseases.
- Cheyne-Stokes breathing CSA, which may be a product of heart failure, stroke, or possible kidney failure.
- Non-CSB CSA associated with other medical conditions, including heart and kidney problems.
- High-altitude CSA, which often appears during sleep at altitudes above 15,000 feet, and induces a form of Cheyne-Stokes breathing with noticeably shorter cycles than classical CSB.
- CSA induced by the use of certain drugs, typically opiates.
Type 4 usually disappears when the patient descends to lower altitudes, and type 5 is best treated by alteration or elimination of the drug regimen, the Mayo article said.
Unfortunately, when CSA is a byproduct of some other disease, the outlook tends to be more discouraging, according to Medline Plus. Treatment of these complex varieties of CSA generally call for aggressive treatment of the accompanying condition by another medical specialist, for example, a cardiologist in the case of heart failure.
“Central patients are more challenging,” said Coppola. “The hard part of people going back and forth requires careful coordination between the breathing physician and the heart care specialist. It’s critical that the sleep doctor coordinate with the cardiologist.”
He paused, then added, “Unfortunately sleep medicine is often practiced in a tunnel.”
In some cases effective treatment of the accompanying illness, if there is one, reduces or eliminates the CSA, but there are often treatments that the sleep physician can pursue in tandem. In cases where CSA is associated with heart failure, the patient sometimes has slow blood flow as well as erratic breathing and consequently is awakened frequently by a sheer lack of oxygen, Coppola noted. “You can’t fix that with CPAP, but oxygen therapy usually helps,” he said.
Aside from those patients, about half of those suffering from CSA can be managed on CPAP alone, Coppola said. In others, he continued, the CSA patient may be assisted by a device known as adaptive servo-ventilator, which monitors the patient’s breathing and kicks in with extra pressure, which may be mixed with extra oxygen, when the normal respiration pattern breaks down. Some patients are helped by unvented CPAP masks, which tend to raise the level of retained carbon dioxide in the blood. This in turn raises the blood’s acidity and that tends to damp down overbreathing. The elimination of overbreathing discourages the shallow underbreathing that typically follows in classic examples of Cheyne-Stokes breathing.
The effect of using an unvented mask is much the same as the effect of breathing into a paper bag, a homespun technique slowing overbreathing, or hyperventilation, as it is technically known.
Rahul K. Kakkar, M.D., director of the Sleep Disorders Center of the North Florida-South Georgia Veterans Affairs Health System wrote in an article published online in 2009 by that two drugs found some times effective in the treatment of CSA: acetazolamide (Diamox) and theophyline (Theo-dur).But he also noted that in certain situations the best treatment of central sleep apnea is nothing at all.
“If the [CSA] patient is not symptomatic, observation may be the only appropriate step. This may be the case in patients who have central sleep apnea during sleep-wake transition, patients without significant oxygen desaturation, or those who experience central sleep apnea during continuous PAP (CPAP) treatment of obstructive sleep apnea.” SleepApnea.org